Аннотация:Four samples of ZSM-12 zeolite (MTW structural type) synthesized using various template types were tested as catalysts in m-xylene isomerization. The functionality of the catalysts was examined using solid-state 27Al NMR spectroscopy, NH3–TPD, and IR spectroscopy of adsorbed pyridine. The effects of the crystallite size, acidity, and phase purity of the zeolites on the composition of the reaction products were investigated. The template used for the synthesis was found to affect the physicochemical properties and catalytic activity of the zeolites.